Might want to try posting on the your question Alaska Outdoors Forum.
Great bunch of members that will do what they can to help.

I did the RV out of Anchorage many years ago, went north and then northeast, then back down south to Seward. We caught a variety of salmon, trout and grayling. Did the trip in late June and the sun barely set, never really got dark. Even did some halibut on a small charter and had a blast. Have fun!

In my experience timing is a pretty big deal. I flew into anchorage, rented an RV and drove down the Kenia peninsula. We went the Last week in Aug and the fishing was really slow for silvers. They were just running a bit late and there was nothing we could do about it. We caught plenty of smaller rainbows and dollies but my family was looking to catch lots of salmon. I didn't mind the tough fishing because I like fishing hard all day anyway but for the others it was a little tough.

It was great at the end of Aug we had almost no mosquitos or bugs. The crowds were not that bad because it was after the Reds had come through and there weren't a whole lot of people out. I think for most serious fisherman either getting a boat to use or hiring a guide for a few days would be a wise investment. For me just the scenery and experience is worth a trip but the DIY road system trip is fun and affordable. You probably won't get the gangbuster fishing that you would get on some fly out or something but at a fraction of the price. For a larger family wanting to spend some quality time I think it's a great idea. I wouldn't expect a whole lot of solitude but I had a great time and will definitely do it again.

Thanks thunderbolt! I will be there Mid of July, and will have 3-4 days guided fishing in Kenai Peninsula, after that, I still have about 1 week hang around Anchorage. So some DIY fly fishing will be a plus for my trip. Really need some first hand experience of where to go and what to fish.

I would highly recommend the book, "Highway Angler" by Gunnar Pederson. It basically breaks it all down for you and explains the different rivers, species, run timing, road access etc. Basically everything you need to know in a nice concise way. I did my first trip almost exclusively off that book. I read it before hand and highlighted the rivers I thought I wanted to hit and then I would read it as we were driving down the road.

I would highly recommend the book, "Highway Angler" by Gunnar Pederson. It basically breaks it all down for you and explains the different rivers, species, run timing, road access etc. Basically everything you need to know in a nice concise way. I did my first trip almost exclusively off that book. I read it before hand and highlighted the rivers I thought I wanted to hit and then I would read it as we were driving down the road.

I'd recommend the flyfishers guide to Alaska as well as the highway angler.

In general, I would recommend fishing around the kenai and its very tribs. Should be lots of dollies and some rainbows. Grayling can be found here and there. You can also drive down to homer and check out the rivers down that away. I am not sure how they fish in July but it is worth the drive down there anyway.

In the other direction, you can drive north on the Parks Highway and hit a number of smaller and medium sized streams that have decent rainbow fishing. The closer you get to Denali you will find more grayling. If you have the time, you should definitely take a trip up to denali although the fishing is just ok up that way.

I'd recommend the flyfishers guide to Alaska as well as the highway angler.

In general, I would recommend fishing around the kenai and its very tribs. Should be lots of dollies and some rainbows. Grayling can be found here and there. You can also drive down to homer and check out the rivers down that away. I am not sure how they fish in July but it is worth the drive down there anyway.

In the other direction, you can drive north on the Parks Highway and hit a number of smaller and medium sized streams that have decent rainbow fishing. The closer you get to Denali you will find more grayling. If you have the time, you should definitely take a trip up to denali although the fishing is just ok up that way.

I would highly recommend the book, "Highway Angler" by Gunnar Pederson. It basically breaks it all down for you and explains the different rivers, species, run timing, road access etc. Basically everything you need to know in a nice concise way. I did my first trip almost exclusively off that book. I read it before hand and highlighted the rivers I thought I wanted to hit and then I would read it as we were driving down the road.